The first attribute you notice about a thing is its existence.
(From the dictionary:
THING, n. Any substance; that which is created; any particular article or commodity.)
On this picture of Sydney, you see many things: the clouds and the sky, but mostly the buildings of the city.
Being aware of a building's existence, you can recognize the building is brought into being: created. It follows that by its existence, the building testifies of its creator.
Using the same 'standard of evidence' for the clouds and the sky above the city, you will recognize that these things are also brought into being: created, and that they also testify of their creator.
If you however would inflate your burden of proof, you will not recognize that the clouds or the sky testify of their creator.
In the latter case, you would no longer have a realistic perspective on things.